Clostridium difficile infection in Tasmanian public hospitals 2006-2010

Objective: To describe the current epidemiology of Clostridium difficile infection (CDI) in Tasmania

Design, setting and participants: Tasmania undertakes continuous surveillance for CDI at all public hospitals. Data on cases of CDI between 2006 and 2010 were examined. All positive tests occurring within 8 weeks of a previous case, and cases occurring in children less than 2 years old were excluded, consistent with national definitions. Only cases identified at public hospitals were included in the analysis

Main outcome measures: The rate of CDI in Tasmanian hospitals over the study period and the ability to demonstrate the effect of variances in surveillance definitions.

Results: A total of 357 cases of CDI were reported over the study period – a rate of 3.08 per 10 000 patient care days (95%CI 2.90–3.27) or 0.94 per 1000 patient separations (95%CI 0.91–0.98) for hospital-identified cases of CDI. Yearly rates for the period 2006 to 2010 were 2.3, 3.2, 2.8 and 3.9 per 10 000 patient care days, respectively. The overall trend was an increase in cases over the study period. The CDI rate from 2009–10 was significantly higher than that from 2008–09. Of the total cases reported,64% were healthcare-associated, healthcare-facility onset (HCAHFO), equating to a rate of 2.1 per 10 000 patient care days over the 4-year period.

Conclusion: The Tasmanian rate of HCA HFO is increasing, and appears to be greater than that reported by other Australian states, but is less than many northern hemisphere regions, where hypervirulent strains of C. difficile are causing increasing morbidity and mortality. It is difficult to compare reported rates of CDI nationally and internationally owing to inconsistencies in study duration, denominator selection, testing effort and testing methodology. This study demonstrates the need for national standards for CDI testing and reporting.